Ensuring the Uniformity of Measurements in the Field of Radiation Thermometry on the Basis of a New Definition of the Unit of Temperature

Abstract

Ensuring the uniformity of measurements (EUM) in the field of temperature measurements, in particular radiation thermometry is one of the main tasks of metrology solved at the state level. The system of metrological support (MS) of radiation thermometry means requires continuous maintenance at the level that meets modern requirements of science, technology, and industry. In order to develop and improve the EUM system in radiation thermometry, a number of measures have been taken in recent years, namely: a new standard base has been developed, including the creation of the State primary standard (SPS) of a temperature unit in the range from 0 °C to 3 200 °C, implementing a new definition of kelvin; a new State verification schedule (SVS) has been developed, which regulates the transfer of the temperature unit to working means from the SPS. To reduce the load on the SPS, decrease the loss of accuracy in the transfer of a unit of thermodynamic temperature and meet the increased requirements for metrological support of measuring instruments, a secondary standard (SS) of a temperature unit was created and studied in accordance with the new definition of kelvin. It included high-temperature blackbody based on fixed points of pure metals and eutectics, a blackbody and comparators that ensure the transfer of a temperature unit in the range from 961.78 °C to 3 200 °C. Based on the results of the research, the created State secondary standard (reference standard) of the temperature unit in the range from 961.78 °C to 3 200 °C was approved by the order of Rosstandart dated November 21, 2022 No. 2931 and fully meets the requirements in accordance with the SVS for temperature MI.